Sint Pietersberg Grottoes

In the St. Pietersberg, a hill at the South side of Maastricht, the reclamation of marl as a building material has resulted in a vast labyrinth of corridors. Even today the walls and ceilings give information about the way in which the ‘block breakers’ worked. On the walls can be found numerous interesting inscriptions and drawings. Two corridor systems in the St. Pietersberg are open to visitors: Northern Corridor System and Zonneberg Corridor System